Cable length
The length of the cable used to connect the surge protector to the network.
The longer the cable, the farther from the outlet you can install the device. On the other hand, a long cable can be inconvenient over short distances. Models on a coil are deprived of this drawback (see "Type"), this moment is compensated by the actual presence of the coil, but they differ in large dimensions and heavy weight. So when choosing, it is far from always worth chasing the maximum length of the wire.
Max. power
The highest power consumption of the connected devices that the surge protector can tolerate without consequences (to be more precise, with which it can work indefinitely without overloads, overheating, etc.).
This limitation is due to the fact that the higher the power at the same voltage, the higher the current passing through the equipment (in this case, through the surge protector); and off-design currents can lead to breakdowns and even accidents. And although in order to avoid these consequences, modern filters often provide various types of protection (see above), however, the operation of protection is still an emergency situation that is best avoided. Therefore, it is worth choosing a model according to this parameter in such a way that the maximum filter power is at least not lower than the total power consumption of the load. And it is best to have a margin of 20 – 30% — this will give additional guarantees in case of various deviations in the operation of the connected equipment.
Separately, it is worth highlighting the situations when the filter is planned to be used for the so-called reactive load — electrical appliances that widely use circuits on capacitors and/or inductors, for example, power tools or refrigeration units. The total power consumption of such devices (written in volt-amperes) can be much higher than the active power (which is indicated in watts). The recommended line filter power in such cases is calculated using special...formulas that can be found in the relevant sources.
Max. energy absorption
The maximum energy absorption provided by the mains filter, namely, the maximum pulse energy at which the device can safely absorb and dissipate it, completely protecting the connected load. The higher this indicator, the more reliable the filter, the more powerful power surges it can handle. In inexpensive models, the maximum absorption is calculated in tens of joules, in the most advanced models it can exceed 1000 J and even 2000 J.
Power switch
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Switch on the body. This function allows you to turn off the power to the load without disconnecting the filter itself from the mains — in other words, it eliminates the need to once again remove the filter plug from the outlet and insert it back. Most often, the switch controls all filter outlets, however, there are models where some of the connectors are bypassed and are always energized, regardless of the position of the switch.
—
A switch for each outlet. This feature makes it easier to manage the power of connected devices: unplugging and plugging individual outlets is usually easier and faster than unplugging and plugging back in. Thus, electrical appliances used with such a filter can be kept constantly connected to it, turning off and on individual outlets as needed.
— Switch for each circuit. The function is used in models with numerous outlets. Allows you to simultaneously disable half of them, leaving the rest working. It combines the convenience of the points listed above and at the same time does not clutter up the device with unnecessary switches.
It is also worth noting that there are models that combine both a switch on the case and a switch for each outlet.
Grounded sockets (type F)
The number of
sockets with type F grounding, provided in the design of the mains filter.
In this case, we are talking about full-size European type F sockets with metal ground clamps on both sides at the edges of the socket. The "socket" in this case means a CEE 7/4 ("Schuko") standard plug. Grounding is required for the safe operation of some types of electrical appliances, in particular, washing machines and other machines that work with water, refrigerators, computers, audio equipment, etc. A detailed list can be found in the reference literature. If you plan to connect such devices through the filter, this filter must have sockets with grounding.
Ungrounded sockets (type C)
The number of
sockets without earthing type C, provided in the design of the mains filter.
In this case, it is assumed that the design of the power filter has a European type C socket (or several such sockets) without grounding. In this case, a "socket" means a CEE 7/4 ("Schuko") plug with two round holes in the central plane of the socket. It is worth choosing a model with this function only if the devices that you plan to use with the filter do not require grounding - otherwise, connecting to such an outlet may be unsafe.
Phone jacks
The number of
telephone jacks provided in the design of the filter.
The presence of such connectors means that the filter can also be used to protect the communication line from various interference. Such protection is especially important when sending faxes and connecting to the Internet over a telephone line — these types of communications are quite susceptible to interference. The minimum number of telephone jacks, if any, is 2, input and output. Many filters with this function have 3 connectors — an input and 2 outputs (to the phone and to the computer); There are more, but extremely rare.
USB A
The number of
USB ports for charging, provided in the design of the surge protector.
Such ports do not perform any other function than powering and charging external devices such as smartphones or tablets. The presence of such connectors in the surge protector can be especially convenient when there is no “230-to-USB” adapter at hand, and there are few USB ports in a computer or laptop and using them for charging is “an unaffordable luxury”.
Max. charging current
The current output by a USB connector when a charging gadget is connected to it.
The higher the current, the faster the battery can charge. However, when choosing, note that in order to use a high current strength, the connected device must also support it. Basically there are
USB with a current strength of 2.1 A,
2.4 A and
3 A.
It is also worth noting that when using several USB ports at the same time, the current strength is significantly reduced.